
Class — i,jl4Siri 
8ook. 



/■ ^. 



U. S. DEPARTMENT OF AGRICULTURE, 

FOREST SERVICE. 

HENRY S. GRAVES. Forester. 



INSTRUCTIONS 



FOR 



MAKING TIMBER SURVEYS IN 
THE NATIONAL FORESTS 

INCLUDING STANDARD CLASSIFICATION 
OF FOREST TYPES. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1917. 



.A? 



D. Of D. 
JUL t7 1917 



r 



^ CONTENTS 



^ Page. 

Purpose of handbook 7 

Principles governing timber surveys 7 

Object 7 

Classification .* 8 

Policy 9 

Funds 10 

Preliminary examination • 10 

Project plan 11 

Approval of projects 12 

Organization 12 

Responsibilities 14 

District office 14 

Forest supervisor 14 

Chief of party 15 

Members of party 15 

Field methods 16 

" Surveys 16 

Mapping 17 

Estimating 18 

Standard of accuracy 18 

Percentage traversed 19 

Estimating unit 19 

Method of traversing area 19 

Diameters 20 

Heights 20 

Quality of timber 21 

Volume tables 21 

Snags and defect 22 

Tallies 23 

Errors likely to occur in estimating 23 

Correction factors 23 

3 



4 CONTENTS. 

Field metliods — Contiiuied. Page. 

Types 24 

Age classes 24 

Silvical data ' 25 

Logging factors 25 

Yield and increment 26 

Field checks and inspection 26 

Progressive steps in timber- survey projects 28 

Map work 28 

Estimates 29 

Logging and silvical data 30 

Project report 30 

Map and estimate data 31 

Descriptive data 33 

Forms 34 

Administrative reports 34 

Records 35 

Equipment 37 

STANDARD CLASSIFICATION OF FOREST TYPES. 

Description of types 40 

Treeless land - 40 

Barren 40 

Grass 40 

Cultivated 41 

Chaparral 41 

Sagebrush 41 

Brush 41 

Woodland 41 

Piilon-juniper 41 

Juniper 42 

Oak 42 

Digger pine 42 

Timberland 43 

Yellow pine 43 

Jeffrey pine . 43 

Sugar pine-yellow pine 43 

Sugar pine-fir 44 



CONTENTS. 5 

Description of types — Continued. 

Timberland — Continued. Page. 

Western white pine 44 

Lodgepole pine 44 

Bristlecone pine 45 

Douglas fir 45 

Douglas fir-spruce 46 

Cedar-white fir 46 

Cedar-hemlock-white fir 46 

Larch-Douglas fir 47 

White fir-larch-Douglas fir 47 

Western hemlock 47 

Cedar 47 

Engelmann spruce 48 

Sitka spruce 48 

Fir 48 

Red fir 49 

Mountain hemlock 49 

Subalpine 50 

Redwood •. 50 

Aspen 50 

Bottomland hardwoods 51 

Jack pine 51 

Norway pine 51 

White pine 51 

Scrub oak 52 

Birch-beech-maple 52 

White spruce 52 

Arborvitae 52 

Tamarack-spruce 52 

Longleaf pine 52 

Titi :.. 53 

Shortleaf pine 53 

White oak 53 



INSTRUCTIONS FOR MAKING TIMBER SURVEYS 
IN THE NATIONAL FORESTS. 



PURPOSE OF HANDBOOK. 

The purpose of this handbook is to present the policy of the 
Service for the conduct of timber surveys and to standardize 
the methods used in the districts to the extent necessary to 
insure reasonably accurate and uniform results. Conditions in 
the districts differ to such a degree that in some respects stand- 
ardization of methods is not felt to be desirable. It will be 
necessary, therefore, for each district to issue supplemental 
instructions to its field officers, based upon the principles herein 
outlined regarding methods not standardized by this handbook. 

PRINCIPLES GOVERNING TIMBER SURVEYS. 

OBJECT. 

The immediate object of timber surveys is primarily to secure 
data needed in connection with timber sales. It is the policy 
of the Service to have a thorough examination made of pros- 
pective timber-sale areas as a basis for determining whether a 
sale is silviculturally desirable, for the timber appraisal, and 
to supply data essential to the preparation of a plan for mark- 
ing, conditions of contract, and sale administration. Since the 
data secured constitute an inventory of the timber resources on 
the tract, and the preparation of a topographic map is a requi- 
site to the project, timber surveys, besides furnishing informa- 
tion needed in timber-sale work, also give data needed in the 
preparation of plans for fire protection and forest improve? 
ments. Since timber surveys are essential to intensive forest 
management, they will be extended as rapidly as funds not 

7 



8 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

required to meet the more immediate administrative needs are 
available. As rapidly as areas are covered by timber surveys 
the data supplied will be made a part of the Forest plan. 

A stumpage appraisal is not necessarily a part of the timber 
survey, since an appraisal may not always be desirable in con- 
nection with a particular project. Sufficient data should be 
secured, however, on the character of the timber and topography 
of the area to make it unnecessary for the appraiser to concern 
himself with other than the layout of the prospective operation, 
the methods and investment required for the exploitation of 
the timber, and such special points as checking the quality of 
the timber as given by the timber-survey crews. The appraiser 
should be able to secure all other data needed, as they relate 
to the timber and area, from the timber-survey reports. The 
test, then, of a satisfactory timber survey is the completeness 
with which it presents the data other than those connected 
with logging methods and costs needed by officers conducting 
appraisals. 

CLASSIFICATION. 

The Service recognizes two classes of timber surveys — ex- 
tensive and intensive. By the former is meant a rough deter- 
mination of the amount and condition of the timber on a given 
area and the preparation of a sketch map of no stated require- 
ments as to accuracy. Any project which fails to meet the re- 
quirements prescribed herein for estimating (see " Estimating ") 
and for map standards 1, 2, or 3, as prescribed by the Instruc- 
tions for Making Topographic Surveys and Maps, will be con- 
sidered an extensive project. The circumstances which make 
extensive projects necessary are such as to preclude a standardi- 
zation t)f method, and no attempt is made in this handbook to 
cover methods solely applicable to them. Each district is au- 
thorizetl to require the use of the methods of conducting ex- 
tensive timber surveys which have been found most satisfactory. 

Intensive timber-survey projects are those which conform Avith 
the estimating standards herein given and to mapping standards 



PRINCIPALS GOVERNING TIMBER SURVEYS. 9 

1, 2, or 3 of the Instructions for Making Topograpliic Surveys 
and Maps. It is with this class of timber surveys that this 
liandboolv deals. 

POLICY. 

Up to and including the fiscal year 1916, 47,291,660 acres have 
been covered by extensive timber surveys, and 20,815,798 acres 
by intensive methods. It is estimated that there remain approxi- 
mately 90,000,000 acres of National Poorest lands bearing timber 
of commercial importance to be covered by surveys before com- 
plete data essential to Forest plans is secured. The completion 
of 1,000,000 acres per year as a minimum, with the present ap- 
propriation, is the basis of the timber-survey policy. 

In addition to the timber surveys made as an incident to small 
sales, local forest officers occasionally have an opportunity to 
secure similar data at odd times when administrative demands 
are not pressing. Timber surveys in spare time should be en- 
couraged to the fullest extent. It is advisable, however, for 
the sake of maintaining satisfactory standards, to have these 
individual efforts directed by instructions prepared by the dis- 
trict forester or forest supervisor. Similarly, crews comprised 
of local officers should be assembled for timber surveys, when 
time or funds are available for the purpose ; but in this case also 
the work should be well directed and controlled. In the conduct 
of many projects it will be necessary to organize special crews. 

The relative importance and the basis for the selection of 
projects are as follows: 

(1) Areas containing timlter which should l)e cut and for 
which bona fide applications for purchase have been received. 

(2) Areas within which desirable sales can undoubtedly be 
made in the near future if estimates and other essential data 
are available. 

(3) Forests or portions of forests in which there is danger 
of overcutting, either in large or small sales : 

(a) In excess of the amounts which should be reserved for 
local needs or to guarantee a reasonable operating life for 
improvements constructed in connection with current sales. 



10 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

(?>) In excess of sustained yield. 

Timber surveys on areas proposed for exchange with States 
or private owners will be undertaken only when specifically 
authorized by the Forester. 

FUNDS. 

Special funds are provided for the conduct of timber surveys, 
from which allotments are made to the districts. These funds 
should be supplemented as far as " contributed time " can be 
made available for the accomplishment of all needed projects 
in the order of importance outlined above. 

PRELIMINARY EXAMINATION. 

A preliminary field examination will be made of all projects 
requiring the approval of the district forester or the Forester, 
unless the essential data have been obtained previously. The 
object of such an examination is primarily to determine the 
need and urgency of the project, in accordance with the policy 
previously outlined, taking into account available funds and 
the practicability and desirability of a sale from silvicultural 
and other standpoints. Incidental to these objects is the se- 
curing of data which will be of value in organizing the work 
and conducting the project efficiently. In order that the essen- 
tial features may be competently passed upon, the examination 
should be made by the chief of party, forest supervisor, or a 
qua'ified member of the Forest force, and a logging engineer 
or other representative of the district office familiar with tim- 
ber survey, timber sale, and silvicultural practice, and with 
appraisal methods and requirements. It is preferable to defer 
a project an entire season, pending a preliminary examination, 
rather than to launch it without definite assurance that the 
expenditure is justified by the project's expediency and im- 
portance. Upon the completion of the examination the ex- 
aminers will notify the district forester of their conclusions 
on the advisability of undertaking the project. If the district 
forester believes the project advisable, the examiners will pre- 
pare a project plan. 



PRINCIPALS GOVERNING TIMBER SURVEYS. 11 

PROJECT PLAN. 

The examination should be sufficiently intensive to permit 
of the preparation of a plan for the project, if approved, which 
will cover : 

(1) The area which should be covered by the timber survey, 
specifying the approximate limits of merchantable timber as a 
basis for adjusting the intensity of the cruise in merchantable 
and unmerchantable timber areas. (See "Estimating.") 

(2) A detailed plan for control, topography, and estimate, 
reference being made to existing instructions in the Instruc- 
tions for Making Topographic Surveys and Maps and in this 
handbook. 

If not covered by outstanding district instructions, there should ' 
be included in the plan a clear explanation of the methods of 
classifying and treating, with reference to the particular proj- 
ect, the subjects listed on Form 494, i. e. : 

Height class. Quality of timber. 

Site. Logging factors. 

Forest type. Reproduction. 

Age class. Notes. 

Condition of timber. 
Detailed instructions also should be included on the appli- 
cation of volume tables ; on the methods of recording estimates 
of timber of merchantable size, by species, whether commercially 
important or not, by diameter breasthigh, and top diameter 
inside bark, and recording trees below merchantable size to a 
minimum of 6 inches diameter breasthigh. 

(3) The availability of existing maps and survey field notes 
for the area and the extent to which these data can be used. 

(4) The size and organization of the party. 

(5) Necessary equipment, transportation facilities, trail con- 
struction required, possible camp sites, etc. 

The engineering and mapping features of the plan will be 
referred to the office or individual in the district office best 
qualified to pass upon them before approval by the district 
forester. The approved plan will constitute the basis for the 



12 INSTKUCTIOXS FOR MAKING TIMBER SURVEYS. 

conduct of the project and will remain in effect until the project 
is completed, unless modified by the district forester or with 
his permission. 

APPROVAL OF PROJECTS. 

All projects involving the expenditure of funds from the special 
timber-survey schedule will be approved by the Forester. A 
transfer of funds between approved projects is permissible with- 
out reference to the Forester. Projects will be submitted to the 
Forester for approval, with the annual report called for under 
"Administrative reports," for consideration by him prior to the 
submission of detailed allotment estimates by the districts. If 
a change in the district's plan for timber surveys, as approved 
by the Forester, arises later, involving a project not previously 
acted upon, the district should immediately notify the Forester. 
Unless already prepared it will not be necessary to submit proj- 
ect plans to the Forester at the time approval of the project is 
sought. The responsibility for the completeness of project plans 
rests with the district forester. Copies of all plans for Forester's 
projects actually undertaken should, however, be submitted for 
the information of the Forester as soon as practicable. So that 
there may be no delay in field work during the most favorable 
season, preliminary examinations should be conducted and plans 
prepared well in advance of the time contemplated for field 
work. 

The district forester will exercise such control over the con- 
duct of timber-survey projects involving other than special funds 
as he may deem desirable to secure satisfactory results. It is 
expected that the instructions issued by the districts in regard to 
timber-survey work will include the procedure to be followed on 
both large and small projects, together with such specific instruc- 
tions applicable to the particular project as may be necessary. 

ORGANIZATION. 

, To the extent found practicable with the funds available 
from the special schedule and by the use of contributed time. 



ORGANIZATION^. 13 

each district should develop an organization for the conduct of 
timber surveys. It is realized that until a definite sum can he 
allotted annually to each district, considerable difficulty will be 
experienced in maintaining a stable timber-survey organization. 
Projects, however, should not for this reason, or because of 
lack of special funds, be deferred when it is practicable to 
organize crews of less experienced men whose services in the 
form of contributed time are available. 

It is intended that the special schedule shall provide for the 
more urgent projects which will permit the early consumma- 
tion of a sale. Although not restricted to this use, it is con- 
sidered primarily a sale-development fund. Provision for sale 
administration should be made from the general-expense funds. 
The special schedule should be used for sale administration only 
with the Forester's approval, when a lack of other funds makes 
this course unavoidable. 

It is essential that the nucleus of the crew consist of men of 
tried experience on timber surveys. There should be enough 
trained men in field parties to obtain the technical data re- 
quired and to insure a corps of experienced men to take charge 
of parties in the future. As a general rule, at least 50 per cent 
of each field party and of each working crew should be men of 
previous experience in Forest Service timber surveys, and pref- 
erably also in scaling, timber-sale administration, and map- 
ping. As a riieans of increasing the efficiency, men selected for 
timber surveys should, when practicable, receive assignments 
to timber sales when not engaged upon survey projects. 

Frequently it may be necessary to employ men temporarily 
to supplement permanent employees in timber-survey crews. 
Such men, unless clearly qualified for assignments involving 
greater responsibility than is customarily put upon them, should 
be appointed field assistants under the conditions and subject 
to the minimum and maximum salary standards established by 
the Selwice for this class of employees. 

In the larger projects it is particularly important that there 
be assigned to the crew one or more men skilled in survey and 



14 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

topographic work who can assist and advise the chief of party 
in attaining the accuracy in control and topography established 
by the Instructions for Making Topographic Surveys and Maps. 
Similarly, in such projects, provision should be made for the 
inclusion in the party, if this work can not be done by the 
topographer, of a man skilled in drafting, to whom will be 
assigned the responsibility, under the chief of party, of com- 
piling the map data collected by the crews and of keeping the 
camp map up to date. 

RESPONSIBILITIES. 

District Office. 

Besides preparing a plan for the conduct of the project, the 
district office will see to it that the party gets the work under 
way in a satisfactory manner. A representative of the district 
office should visit each party, preferably with the supervisor, 
when the field work begins, or as soon thereafter as practicable", 
to see that the work is conducted along the lines outlined by 
the plan and that the methods prescribed are thoroughly under- 
stood. If any changes in the plan seem to him desirable he 
should report them to the district forester, or, in case previous 
authority has been given him by the district forester, put the 
changes into effect immediately. The district office will also 
conduct such additional inspections of the work of the crews 
as may be found necessary to conform with the instructions 
under " Field checks and inspection." 

Forest Supervisor. 

There should be a clear understanding between the district 
office, the supervisor's office, and the chief of party concerning 
the relation of the project organization to the Forest organiza- 
tion. The forest supervisor will be expected to render to the 
timber-survey party every assistance practicable. In its turn, 
the timber-survey organization will be expected to assist the 
supervisor to the fullest extent possible in meeting any serious 
fire hazard. The extent to which cooperation between the super- 
visor and the survey crew can be carried is for the district 



ORGANIZATION. 15 

forester to determine in each case. Unless expediency requires 
another course, the timber-survey organization should be placed 
under the direction and supervision of the forest supervisor, 
who should be held responsible for the efficient execution of the 
project. He should be made to feel a direct and personal 
responsibility for the manner in which it is conducted, as 
well as for the accuracy of the data secured and manner of its 
presentation. 

Chief of Party. 

Direct responsibility for the conduct of the work on the 
ground will rest with the chief of party, who should be selected, 
subject to the approval of the district forester, for his experi- 
ence in timber surveys and general National Forest work, and 
his ability to handle the crew. The chief of party will be 
expected to see that the project plan is thoroughly understood 
and followed by the men, to maintain discipline, to exercise 
ample checks, to arrange for the assembling jtnd correlating of 
data so that they can, if necessary, be turned over to a suc- 
cessor. He should also become sufficiently familiar with the 
conditions on the area, as a whole, to be able to prepare at the 
completion of the project a comprehensive report. The chief of 
party will be subordinate to the forest supervisor, unless the 
matter is arranged otherwise by the district forester. 

Aside from general supervisory duties, which must necessarily 
take precedence over other work, the relative importance of the 
duties of the chief of party is as follows : 

(1) Periodic instruction of strip crews in their duties and 
checking their performance. 

(2) Check estimates. 

(3) Current compilation of map data in building up project 
maps. 

(4) Assembling data for stumpage appraisal. 

Members of Party. 

The topographer or draftsman, as the case may be, will 
assist the chief of party in conducting and supervising the 



16 IXSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

control and topographic work done in connection with the 
project, and will, if best qualified to do so, instruct the men 
in the details of topographic methods and in preparing their 
field sketches for use in the compilation of the camp map. 

Arragements should be made to have a member of the crew 
who can best be spared for the purpose relieve the chief of 
party of as nmch camp routine as possible, such as ordering 
and checking property, supplies, etc. In parties of 10 men or 
more, it may be found necessary to have an assistant chief of 
party to take over work of this character, leaving the chief of 
party free for the required amount of supervision and such 
original work on his part as may be necessary. 

If not included in the general district instructions, the plan 
for the specific project should give in as much detail as prac- 
ticable : 

(1) The duties of the members of the party by classes. 

(2) What data each class is to collect. 

(3) The object of these data. 

By every possible means the whole timber-survey force should 
receive an insight into the broader phases of the work and its 
ultimate results.^ This is of the utmost importance in arous- 
ing a personal interest in the work, which is essential to a 
high degree of accuracy and efficiency. 

FIELD METHODS. 

SURVEYS. 

The Topographic Surveys Manual outlines the Forest Service 
standards of mapping and the methods for securing the degree 
of accuracy required under each standard. Standards are fixed 
for primary control, secondary control, and interior lines. The 
aim of these standards is to secure maps of sufficient reliability 
to be accepted as a part of the permanent Service map record. 
The degree of accuracy attained under them will permit the 
use of the maps for all administrative needs. 

As far as practicable with the funds available, all surveys 
and maps made in connection with timber-survey projects \yill 



FIELD METHODS. 17 

conform to one or a suitable combination of the standards out- 
lined in the Instructions for Making Topographic Surveys and 
Maps. Standards 2 and 3 of the above Instructions, or a suitable 
combination of those standards, will be used for surveying and 
mapping on intensive timber-survey projects. The use of stand- 
ard 1 survey and map methods solely for timber-survey pur- 
poses will be permitted only with the approval of the Forester. 
The Forester's approval must also be secured for the use of 
funds from the special schedule for the extension beyond the 
limits of the project of control lines or stations which are not 
essential to the surveying and mapping of it under tlie standard 
selected. 

The selection of methods from those outlined for the standard 
is discretionary with the district forester. Where a combina- 
tion of methods prescribed for secondary control and interior 
lines under standards 2 and 3 is used the principle of con 
sistent accuracy should be followed — i. e., the accuracy of the 
control should not fall below the standard followed in run- 
ning the interior lines, since the inaccuracies in control gauge 
the accuracy attainable in interior detail. 

Where not enough funds are available to conduct a project in 
conformity with the survey and map requirements of standards 
2 and 3 the district forester will select such methods, prefer 
ably in conformity with those prescribed in the Instructions 
for Making Topographic Surveys and Maps, as will give the 
most satisfactory results for the funds available. Funds from 
the special schedule for timber surveys will be used on such 
projects only with the approval of the Forester. 

MAPPING. 

The scale of maps in timber-survey projects will be no less 
than 4 inches to 1 mile. 

The standard contour interval will be 50 feet. A departure 
from the standard will be permitted, in the discretion of the 
district forester, only when, because of choppy topography or 
for other reasons, a closer contour than 50 feet is necessary 

86656—17 2 



18 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

to nlfoid detailed map data required by tlie lo^-.uiiiK ei),jj;ineer 
in ma lei Hi;- an appraisal of the timber, or on Ions, vSteep slopes, 
where a greater interval than 50 feet will adequately depict the 
topography of the area and will in no wjiy detract from the 
value of the map for appraisal or timber-sale administration 
purposes. In no case will a smaller interval than 25 feet or a 
greater interval than 100 feet be used. 

Separate types and age classes and merchantable and un- 
merchantable timber areas of 10 acres or more in extent will 
invariably be mapped. Ordinarily, arens sniMller than 2^ acres 
need not be mai)ped. 

The symbols standardized for the Service will be used (»n 
timber-survey projects (see Instructions for Making Topographic 
Surveys and Maps). AMiere features to be included on timber- 
survey maps have not been standardized the district should use 
the symbols already employed by it or devise suitable ones. The 
extent to which symbols will be empl<>yed to indicate features of 
topography which affect logging transportation should be de- 
termined upon the advice of the logging engineer. The location 
of clilfs. ledges, rim rock, rock slides, patches of broken rock, or 
bed outcrops, swamps, marshes, flats, and l)enches has fre- 
quently been of material assistance to logging engineers iii 
making an appraisal of the timber, and slKudd be recoi-ded 
uniformly on timber-survey maps. 

The instructions in the Instructions for Making Topographic 
Surveys and Maps will be followed in monumenting stations and 
surveys on all permanent lines and in recording the monuments 
and descriptions. 

ESTIMATING. 

A record of the estimate will be kept upon Form 494 in ac- 
cordance witb the instructions outlined in the plan for the 
project. 
Standard of Accuracy. 

The standard of accuracy to be sought in estimates is 5 per 
cent plus or minus on areas over a section in extent, and 10 
per cent plus or minus on areas of a section or less. 



FIELD METHODS. 19 

Percentage Traversed. 

Except on areas best adapted to the use of the plot or lUU 
per cent estimate method (see "Method of traversing area") 
and in District 7. in which the district forester will prescribe 
the percentage of area to be covered (subject to tlie minimum 
requirements lierein given), the standards to be followed in 
securing estimates of the timber on intensive projects are: 

(1) Estimate the timber on 10 per cent of the ground con- 
taining connnercially important species of merchantable size 
within tlie lumndaries of probable sale areas. 

(2) Estimate the timber on from 2^ to 5 [hh- cent of the 
areas containing timber not merchantable in size and timber 
of minor importance commercially. 

(8) Traverse oi- plane-table burns. i-i<lges. stands of young 
growth, and treeless areas to the extent necessary to obtain 
topogi'aphic data and type boundaries. 
Estimating Unit. 

The unit of estimating in surveyed country will be the 40 : 
and in unsurveyed, the hypothetical square 40 or some other 
convenient unit not exceeding 160 acres selected by the chief 
of party in consultation with the supervisor and approved by 
the district forester. On the purchase areas oil which the 
rectangidai- form of survey has not been used the unit of esti- 
mating for the jjroject will be kept as small as practicable, so 
as to conform to the practice on lands surveyed rectangularly. 
Method of Traversing Area. 

The standard method of traversing areas will be by strips 
at least 1 chain in width on which the trees will be tallied by 
diameter breasthigh and unit of height to a given top diam- 
eter. The advantages of this method are its adaptability to 
both mapping and estimating practice, the opportunity given 
to systematize the courses run, and the probability that the 
areas traversed as a whole will represent average conditions on 
the tract. 'Scattered or isolated stands of comparatively small 
extent which can be more conveniently and accurately esti- 



20 INSTRUCTIONS FOE MAKING TIMBER SURVEYS. 

mated by the plot or 100 per cent estimate method may be so 
estimated, the use of the plot method being subject to the 
minimum standard requirements in percentage of area to be 
covered. With this exception, other methods than the strip 
method will be used only with the Forester's approval. 

Diameters. 

It is essential that great care be taken by the crews to 
secure the correct diameter breasthigh of trees on the area 
traversed. Ocular measurements of diameter should be made 
only by those proficient in judging diameter measurements. 
Even these should frequently check their judgment by actual 
measurements. The extent to which actual measurement will 
be done on each project will be determined by the district 
forester, subject to the minimum requirement that 25 per cent 
of all commercially important trees of merchantable size will 
be actually measured, preference being given to trees of the 
larger diameters. 

Trees below merchantable size to a minimum diameter breast- 
high of 6 inches may be recorded in such manner as the dis- 
trict forester may direct. Material under 6 inches diameter- 
breasthigh will be classed as reproduction. 

Heights. 

In estimating volume by board measure the best method of 
determining heights is to estimate the number of logs of given 
length in each tree of merchantable size on the area traversed, 
the number of logs being rounded off to the nearest number of 
the given length. Another method, adapted to even-aged Douglas 
fir stands and stands of lodgepole pine and western white pine 
of uniform height, is to record the total height of each tree or 
the prevailing height of the timber in its relation to three or 
more height classes established for the project. In both instances 
the volume of the timber is obtained from volume tables, based in 
the first case upon diameter breasthigh and number of logs, and 
in the latter case on diameter breasthigh and total height. 
Heights should be taken in current work from time to time with 



FIELD METHODS. 21 

the cruiser's stick. These should be checked by occasional meas- 
urements made with a hypsometer or by pacing windfalls. 

The method to be followed in determining heights of timber 
of merchantable size will be by the number of logs per tree, 
except under the following conditions : 

' (1) In even-aged stands of Douglas fir and in stands of lodge- 
pole pine and western white pine of uniform height, to which 
existing height-class tables are believed applicable or for which 
applicable tables can be constructed readily, the alternative 
method given above may be employed in the discretion of the 
district forester, provided a distinct saving in cost can be effected 
thereby. 

(2) When the material estimated is to be converted into spe- 
cial products, such as poles, ties, shingle bolts, etc., the estimate 
may be made on the basis of the appropriate market units. 

(3) When volume is to be estimated in cubic feet an appro- 
priate method of determining and recording heights will be 
prescribed by the district forester. 

Quality of Timber. 

Ultimately it is hoped that the quality of timber in the stand- 
ing tree may be determined by and receive a log-grade classi- 
fication. Therefore this practice should be adopted in timber 
surveys as rapidly as the crews develop capacity for it. It is 
followed to some extent in the Northwest at the present time 
on the basis of the standard specifications for logs in tlie general 
market. The classification of logs in standing trees in accordance 
with these specifications requires more experience than most 
members of timber-survey parties have had, so that for the 
present its general adoption is not considered practicable. When 
the designation of quality by log grade is for any reason imprac-^ 
ticable, it will be the policy of the Service to express quality 
by clear bole or number of clear logs of stated minimum length 
and diameter, as provided by Form 494. 
Volume Tables. 

Arrangement will be made, as a part of the preparation of the 
project plan, to assemble volume tables for use by the crew, un- 



22 IXSTRL^CTIOKS FOR MAKING TIMBER SURVEYS. 

less the district instructions already include .suitable volume 
tables or the preparation of volume tables constitutes a part of 
the project. Every opportunity should be taken to test volume 
tables now in use, with a view to determining the extent to 
which they are applicable to timber in different parts of the 
district. 

The most prolific sources of error in the application of volume 
tables, to which particular attention should be given in inspec- 
tions, are : 

(1) The use by the estimator of a different top diameter 
from that upon which the table is based. 

(2) Differences between the top diameter upon which volume 
tables are based and those actually followed in logging. 

(3) Differences between the form factor of the timber on 
which the volume tables were made up and that of the stand 
being estimated. 

(4) Differences in thickness of bark. 
Snags and Defect. 

Form 494 provides for the number of snags of a given mini- 
mum diameter and height, the per cent of cull by species, and the 
extent of damage (expressed in per cent) by fire, insects, or 
other agencies. A record of the number of snags of sufficient 
size to constitute a fire menace is needed for use in prescrib- 
ing fire-protective measures in timber-sale contracts. On proj- 
ects which will be followed immediately by sales involving a 
tree-sanitation contract clause it will also be necessary, as an 
nid in appraisals, to have a record on the form of the number of 
unmerchantable diseased trees. 

It is highly important that members of the crews be trained 
in determining defect in standing timber. With inexperienced 
crews doubtless it will be found advisable to use an average cull 
factor by species based upon the judgment of the chief of party 
and logging engineer and the per cent of defect found to exist 
on timber sale areas within the same region. AVhere individual 
species are very defective, a separate cull factor should be as- 
cribed to them. Where individual trees "are exceptionally de- 



FIELD METHODS. 23 

l\»<tive it is iieriuissible to carry Ji special record of them in 
such a way as to indicate the percentage of defect, as by enter- 
ing a percentage tignre in a circle rather than the customary dot ; 
thus entered in the appropriate hhmk (ai Form 494 would 
mean a tree 60 per cent defective. 

Tallies. 

Tallies will he kept separately by forties, logging units, and 
areas of merchantable and unmerchantable timber. Separate 
tallies for each type and age class may be required in the dis- 
cretion of the district forester, except that a separate tally of 
scattering timber on areas which are mapped as unmerchant- 
able will always be required. Where tallies are not changed for 
type and age class, all types and age classes traversed will be in- 
dicated on the back of Form 494, with the proportion of each. 
Errors Likely to Occur in Estimating. 

The errors most likely to occur in estimating are : 

(1) Inaccuracy in estimating defect. 

(2) Inaccuracy in the use of volume tables. 

(3) Mistakes in measuring or guessing at diameters. 

(4) Errors in determining heights. 

(5) Failure to use the correct width of strip. 

(6) Failure to include all and only trees actually within 

the strip. 

Steps necessary to eliminate or reduce these errors to a 
minimum are outlined under " Field checks and inspection." 

The practice of allowing for cull by reducing the diameter 
or height of individual trees will not be followed ; nor, in deter- 
mining the number by which to multiply the volume of a strip 
to get the volume of a forty, will the volume qf the strip be 
increased or decreased to bring it to the estimator's general 
impression of the forty. 

Correction Factors. 

It should be understood that in broken stands, interspersed 
with parks, etc., the acreage on the strip and the acreage of 
timber on the forty or other unit are entirely distinct, The 



24 IXSTEUCTIONS FOE MAKING TIMBER SURVEYS. 

latter is not any prescribed multiple of the former. The strip 
should stand by itself and its timber area and volume be com- 
puted as a basis for the determination of the total volume on 
the unit. 

Where the strip represents more or less than the prescribed 
per cent of area in the forty, this will be allowed for mechan- 
ically by proportion, and the correct number used in multiply- 
ing the volume of the strip to secure the volume of the forty. 
The acreage of timber on the forty is divided by the acreage 
of timber on the strip, and the result multiplied by the volume 
on the strip to give the volume on the forty. For example, when 
Che map for the forty shows 10 acres as grassland and 30 acres 
timber, and 8 chains of the strip were run through grassland 
and 12 chains through timber : 

Area of strip in timber =1.2 acres 
A creage of timber on forty _ 30 
Acreage of timber on strip ~ 1.2 

Assuming that the volume on the strip is 15,000 feet, the 
volume of timber on the forty would .be 375,000 feet. 

Where tallies are kept separately by types and age classes 
and part of the forty is in one type or age class and part in 
another, tlie proper number by which to multiply the volume of 
each tally sheet is determined in the same way. 

TYPES. 

The "Standard classification of forest tyi^es " (see pp. 38 
to 53) will be used in naming and recording types. 

AGE CLASSES. 

It is important that in designating and recording age classes 
the distinction between size, merchantability, and age be borne 
clearly in mind. The use of size as a constant indication of age 
will result in error in the case of small, scrubby, decadent, or 
subalpine stands. Size is given in the estimate, while special 
provision for mapping merchantability should be made by the 



FIELD METHODS. 25 

use of suitable symbols designating merchantable, in contrast 
to unmerchantable, stands. The simplest method of designating 
age classes is by the use of descriptive terms, clearly under- 
stood, which cover a range of age classes readily distinguish- 
able, such as: ^ 

Overmature, over years old. 

Mature, between and years old. 

Intermediate, between and years old. 

Poles, between and years old. 

Saplings, between and years old. 

SILVICAL DATA. 

To be of value for subsequent use, silvical data must be so 
expressed as to permit their being assembled in comprehensive 
terms and mathematical form for the whole tract. Loose, gen- 
eral descriptions are useless. In order to simplify the collection 
of these data and permit their ready compilation. Form 494 pro- 
vides for a statement of the condition of the timber, i. e., thrifty, 
mature, and decadent, in terms of percentage ; and for a state- 
ment regarding reproduction in terms of density of stocking, 
i. e., no reproduction, one-third stocked, two-thirds stocked, and 
fully stocked. The form provides also for a statement of the 
proportion of the total reproduction on the area which the re- 
production of each species represents. Ordinarily it will be 
necessary to report reproduction only in uneven-aged stands or 
^\•Jlere it constitutes the cover. 

LOGGING FACTORS. 

Observations on ground cover, ground surface, and topography 
should be made from the standpoint of their effect upon logging. 
Reproduction, so far as it is a factor in logging, should be con- 
sidered in recording undergrowth. Form 494 provides for a 
brief statement on logging factors, under which is to be given 
the amount of undergrowth and windfall expressed in terms of 



26 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

density, of bowlders and broken rocks expressed in terms of 
quantity, and such other factors as will indicate the ease or 
difficulty of the logging. To be of greatest value, notes secured 
on logging" factors other than those specifically provided for on 
the form sliQuUl conform to those desired l)y the logging engi- 
neer and incorporated in the project plan. 

YIELD AND INCREMENT. 

So far as practicable the data secured on timber-survey proj- 
ects will be utilized in the construction of yield tables showing 
the actual yield of the watershed covered. Actual or empirical 
yields of the area in question may be secured from data on even- 
aged stands where the tallies are kept separate by type and age 
classes and in uneven-aged stands upon which the area of growth 
lielow merchantable size is determined. 

In even-aged stands the tallies of each age class in each type 
are combined to give the average volume per acre of the age 
class. Each age class will thus give a point on a curve of yield 
for the area covered. 

FIELD CHECKS AND INSPECTION. 

Provision will be made in all project plans for specific field 
checks and inspection. Effective checks not only on the esti- 
mates, but on the maps and notes secured, are indispensable. 
These checks should be made during the progress of the work 
by the chief of party or a member of the party especially fitted 
for it, by the supervisor or his representative, and by members 
of the district office. Every man connected with timber surveys 
should understand that his work may be checked at any time. 

It is the duty of the chief of party to have frequent check 
estimates made and to instruct members of the crews in all 
phases of their work. In order to insure that adequate atten- 
tion is given to these important features of the project, each 
party chief should be required to make or have made a mechan- 
ical check estimate, Mith the original crew, on at least 3 per 



FIELD METHODS. 27 

cent of the strips covered, and to spend at least one-half day 
with each crew every 10 days for the purpose of instructing the 
men and checking up other phases of their work. The essential 
reason for the conduct of a mechanical check is to keep the 
accuracy of the estimates at a high standard by affording a 
thoroughly accurate basis for checking the work of the crews 
and pointing out to them the particular respects in which their 
estimates are in error. In order that the check estimate may 
serve this purpose, exact methods, such as chaining width of 
strip at frequent intervals, obtaining heights by hypsometer, 
etc., will be used as far as possible. The check estimate may 
be used also, ns a basis for the correction of original estimates 
the accuracy of which is not within the standard prescribed, iDut 
its use for this i)urpose is considered incidental to its value for 
the maintenance of a high standard of accuracy by the crew. 

In securing a check on the general efficiency of the crews par- 
ticular attention will be given to the following points : 

(1) That the vertical and horizontal ties at the ends of the 
strips are witbin the degrees of accuracy prescribed by the plan. 

(2) That the crews are exercising the proper care in the 
width of strips within which the timber is tallied. 

(3) That tlie crews understand and are securing satisfac- 
tory results in platting topography. 

(4) That proper care is taken in the measurements of diame- 
ter and height. 

(5) That proper allowance is made for defect. 

(6) That the quality of timber is properly ascertained and 
recorded. 

(7) That the acreage correction factor is correctly applied. 

(8) That the volume tables in use are applicable. 

(9) That the silvicultural condition of the timber is cor- 
rectly interpreted and recorded. 

(10) That there is full understanding and proper recording 
of the important logging factors. 

(11) That notes required by the project plan and Form 494 
are understood and properly entered. 



28 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

Obviously, in the larger parties the chief of party must have 
assistance to follow the work of the crews so closely. Arrange- 
ment for this assistance can be made by the assignment of an 
assistant chief of party or by using for this purpose well-quali- 
fied members of the crew. Checks or inspection made by the 
supervisor or representatives of the district office will not in 
any degree lessen the obligation of the party chief to meet the 
requirements above prescribed. Such checks will supplement 
the minimum required of the party chief. 

It is essential that early in the progress of the project a log- 
ging engineer or other highly qualified timber appraiser visit the 
party in order to give advice on all factors relating to the esti- 
mate and logging. He should conduct such checks as will sat- 
isfy him that the data required by the project plan as it relates 
to the estimate and logging factors are understood thoroughly 
and recorded properly. Further, a representative of the district 
office should visit the project during the field season and inspect 
the work from the standpoint of the sufficiency of silvicultural 
data secured. 

An excellent method by which to control and direct the field 
work of the crews is to plat on the camp map the location of all 
interior lines run or to provide a skeleton map on which can be 
platted in colors by contrast the location and extent of areas 
covered by the crews. 

PROGRESSIVE STEPS IN TIMBER-SURVEY PROJECTS. 

In general, the progressive steps by which data are obtained 
for the completion of timber-survey projects are as follows : 

MAP WORK. 

(1) A control or camp map is begun by preliminary drafting 
work before field work begins. On this map are entered suc- 
cessively — 

(«) Preliminary data from General Land Office surveys, 
United States Geological Survey triangulation or bench marks, 
and data from any other surveys available. 



TIMBER-SURVEY PROJECTS. 29 

(6) Location of courses and points secured by the timber- 
survey crew for control, primary and secondary ; General Land 
Office lines retraced, hypothetical section lines traversed, etc. 

(e) Location and course of interior lines, covering all parts 
of the project. 

This map is preserved as an important part of the permanent 
project record, and is of great value in subsequent administra- 
tive work. 

(2) Field sketching plats are prepared by the crews, cliecked 
with one another as fast as completed, initialed by the men 
making them, and submitted to the party chief or draftsman. 

(3) The project topographic map showing all topography, but 
no type, age class, area of merchantable and unmerchantable 
timber, or site-quality data, is compiled in camp by the party 
chief or draftsman as the work progresses. Current compila- 
tion permits checking any doubtful points while the party is on 
the ground. It is of special importance to have this map kept 
current with work on interior lines. 

(4) A project type map (and, if desirable, site quality, age 
class, and merchantability area maps) is made up currently in 
camp, the types being shown by appropriate lines, colors, or 
symbols. Subsequently, maps showing these data in colors are 
produced on white prints from the tracing of the project topo- 
graphic map. 

ESTIMATES. 

(1) If volume tables are not already available they are pre- 
pared from the detailed estimate data secured by the crews for 
use in computing volume. 

(2) The timber on the areas traversed by the crews is tallied 
by diameter and number of logs, height class, and unit of prod- 
uct, or cubic-foot unit, as the case may be, for each forty or other 
area selected ; the percentage of defect estimated ; and the area 
of timber on the strip recorded. The area of timber on the 
forty is later computed from the map. 

(3) From the above are computed: • 



30 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

(<i) The gross and net volume of each species (ov group of 
species) on the area traversed. 

(h) The net volume of eacli species (or group of species) on 
tlie forty or other unit. 

(e) The total net volume on the forty or other unit. 

(4) The figures obtained by forties or other units under (3) 
are entered by species (or group of species) on summary sheets 
in order to secure a summary estimate by larger appropriate 
divisions, such as sections, townships, and logging units. 

(5) Similarly, data are summarized by types, age classes, and 
merchantability area, by section, township, and logging unit, or 
by other appropriate larger divisions. 

LOGGING AND SILVICAL DATA. 

Notes are kept currently on Form 494 on the condition and 
quality of the timber, reproduction, and factors affecting log- 
ging. The major data under these heads are recorded by gen- 
eral descrijitions, which lend themselves to convenient summar- 
izing by forty, section, township, logging unit, or other division. 

PROJECT REPORT. 

It is rlie duty of the chief of party to bring into sliape for pres- 
entation in working plan or report form all data collected in 
connection with the project. Upon him rests the responsibility 
of properly compiling the map and estimate data and coordinat- 
ing the notes secured by the crews and by him independently on 
the condition and quality of the timber, logging factors, and 
other data relating to stumpage appraisals, and on such special 
problems as have arisen in connection with the project. Logging 
engineers and other representatives of the district office should 
add to the data compiled by the chief of party as much as they 
can and render him such assistance as he may need in the 
preparation of a complete report for the area. Unless the mate- 
rial which is to be included by the chief of party in the project 



PROJECT REPORT. 31 

report and the form in which it sliould appear are prescribed in 
the district timber-survey instructions, the district forester wiil 
prescribe them for each project. Tliis can be done best in out- 
line form. 

MAP AND ESTIMATE DATA. 

So far as practicable all data will be compiled in the held as 
sox>n as possible after they are available ; and if this is imprac- 
ticable, compilation will be completed before the beginning- of the 
following field season. This is necessary : 

(1) To make data innnediately available for use. 

(2) To obtain the obvious benefits of compilation while the 
data are fresh in the minds of the men. 

(3) To discover errors and omissions while there is the best 
opportunity for correcting them. 

(4) To prevent the loss of important data through sudden 
changes in personnel. 

(.")) T(» jtrevont lost motion in ultimately fornndating working 
I»lans. 

In addition to reducing to a mininuim the work of preparing 
the project report, the object should be to leave all data, notes. 
etc., in such form that a new man taking over the work will 
have the full benefit of what has already been done. 

Topography, at least, should be transferred from the field 
sketches as fast as it is secured. Other map data, such as type 
and age class boundaries usually can be transferred to best 
advantage at the same time. 

If final maps are to l)e prepared in the Office of Maps and 
Surveys at Washington, the field data, with necessary correc- 
tions, should be traced on tracing or linen paper, with topog- 
raphy and culture on one sheet and type lines, etc., on a second. 
From these tracings, the Office of Maps and Surveys will prepare 
photolithographic prints of any class of maps that falls within 
the standard printing list and photographic prints of other 
classes of maps needed. Each sheet may contain a township, 
logging unit, or other convenient unit, as desired. 



32 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

If final maps are to be prepared in the district office, the dis- 
trict project plan should outline the particular method to be 
followed in camp compilation. 

In all cases copies of final topographic base, type, age class, 
merchantabilitj^ area, and estimate maps, singly or in combina- 
tion as prepared, will be forwarded to the Washington office 
for the Forester's files. 

Estimates should be computed in the field, if practicable, or 
as soon after the completion of the field work as possible. All 
important steps in computations must be carefully checked. If 
no cross checks on results are available, the computation must 
be made by two persons or twice by the same person. 

Estimates may, in the discretion of the district forester, be 
tabulated, placed on separate copies of the topographic base 
(by putting them on separate tracings which can be superposed 
over the topographic base and printed in one operation), or 
placed on a plain sheet as a graphic table to be bound vis-^-vis 
to the topographic map. 

For convenience in stumpage appraisal, estimates will be 
summarized by blocks and logging units and such other units or 
combination of units as may seem advisable. In surveyed coun- 
try they will also be summarized by sections and townships. 
Where separate tallies are kept for each type and age class and 
the data is of advantage in stumpage appraisal the estimates 
should also be summarized by age classes within each type. 

In order to put the estimate data to its highest use and to 
permit a later adjustment of it if any specific sale should make 
this necessary, the following summaries will be of value : 

(1) The average number of logs per M feet board mjeasure, 
for each species, worked out from volume computations. 

(2) A summary estimate by log grades or other quality 
classes. 

(3) The volume of inferior species in the smaller sizes or 
of commercial species in the smaller sizes where desirable, so 
that it may be eliminated, if necessary, in the consideration of 
prospective sales. 



PROJECT REPORT. 33 

(4) The volume of all abnormally defective trees to which 
average cull factors are not applicable, so that it may be elimi- 
nated, if need be, in preparing an estimate for a prospective 
sale. 

(5) Taper tables upon which a revision of the estimates may 
be made in case closer or poor utilization than that upon which 
the estimate was based is secured. 

Further summaries by appropriate units, such as the number 
of trees by species and diameter classes, the average per cent 
of defect by species, and the number of snags and diseased 
trees may also be found desirable in localities where these 
factors are an important feature in appraisals and timber-sale 
administration. 

DESCRIPTIVE DATA. 

The descriptive portion of the report will cover all points 
essential to a complete understanding of the area from a silvi- 
cultural and logging standpoint which are not given on the 
maps or in the estimate tabulations. It should be brief and 
specific, presenting information in tabular form whenever pos- 
sible. Photographs may often be used to good advantage. 
Since the immediate use to which the data are put will be for 
the promotion of timber sales. Form 578a will be found helpful 
for reference in its preparation. 

The following outline for this portion ot the report is sug- 
gested as covering the more essential points. If further factors 
are necessary for a complete understanding of conditions, they 
should be included. 

1. Introduction. 

a. History and personnel of the project. 
&. General location of project, 
c. Unit divisions. 

2. Status and ownership. 

3. Silvical description (compiled from Form 494). 

a. Brief description of each type and age class, with 
the proportion and area of each. 

&. The percentage of thrifty, mature, and decadent 
timber. 

86656—17 3 



34 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

c. The percentage of timber killed or damaged by 

fire, insects, or other agency, with a statement 
of the nature of the damage. 

d. The percentage of each degree of stocking, with 

reproduction ; the occurrence, size, etc. 

4. Logging data. 

A record compiled from Form 494 and including a 
brief descussion of the abundance of undergrowth, 
windfall, bowlders, broken rock, and other surface 
or topographic factors which have a direct bearing 
upon logging. 

5. Recommendiitions for management. 

If desirable, the chief of party may be requested to 
submit recommendations concerning the future 
management of the area and the principles that 
should be followed in timber-sale administration 
in the event of a sale. 

FORMS. 

Form 878 (buff-colored paper), 878a (tracing linen), 87Sb 
(imitation vellum), and 878c (celluloid) have been adopted as 
standard for all classes of map work in connection with timber- 
survey projects, and Form 494 for recording the estimate and 
silvical and logging data. Aluminum Tatum hglders of suitable 
size will be provided for use with these forms and may be had 
upon requisition of the property clerk. The use#3f other forms 
for mapping and recording estimates or for silvical and log- 
ging data will be permitted only with the Forester's approval. 
Each district may, however, adopt for camp use such additional 
forms, estimate summaries by logging units and townships, 
forms for requisitioning and invoicing supplies and equipment, 
and the like, as will simplify the compilation and camp duties 
of the party. 

ADMINISTRATIVE REPORTS. 

Brief reports at least monthly should be required, in order 
to keep the supervisor and district forester in touch with the 
work. It is not intended, however, that such reports shall sup- 
plant field inspection to any degree. 



RECORDS. 35 

The data on timber surveys required for the annual statisti- 
cal report (Form 446) will be submitted as heretofore. 

The district forester will also submit at the end of each field 
season, and not later than February 1, a record of timber sur- 
veys during the preceding calendar year as outlined in the form 
on page 36 and a list of projects recommended for the ensuing 
fiscal year. He will also submit a statement showing the need 
for each project, its acreage, estimated cost, the character of 
map and estimate required, and the period necessary for its 
completion. Upon these lists the Forester will base tentative 
allotments from the special schedule for the guidance of the 
districts in submitting their detailed estimates. 

RECORDS. 

Simple plans for filing field data and correspondence in camp 
should be included in the district instructions or project plan. 
Upon the completion of the project all original data will be 
considered a permanent record and filed in the supervisor's 
office. 

A record by major lines of work will be kept of the current 
costs on each project. This record will be in sufficient detail 
to permit an annual report to the Forester on Form 446 by 
fiscal years, and as herein outlined (see form on p. 36) by 
calendar years. Where the district keeps a more detailed rec- 
ord of costs than that called for by the form, a copy of the com- 
piled district report will suffice. 



36 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 



Outline indicating data on completed timber- survey projects to 
he furnished the Forester by each district at the end of each 
field season (for the calendar year). 





Proj- 
ect. 


Acres 
esti- 
mat- 
ed. 


Per 

cent 
of 
area 
cov- 
ered. 


To- 
tal 
cost 
of 
proj- 
ect. 


Control. 


Cost per acre. 


Forest. 


Num- 
ber 
of 

miles. 


Cost 
per 
mile. 


Con- 
trol. 


To- 
pog- 

ra- 
phy. 


Esti- 
mate. 


To- 
tal. 




























































































































































Total 


XXX 
XXX 


XXX 


XXX 






XXX 


XXX 


XXX 


XXX 


TCTCTT 


Average 


XXX 


XXX 















Note 1. The costs given should represent the total expenditures on the project. 
Compilation and other office work, and miscellaneous costs, such as supplies, ineffec- 
tive days, moving, leave, travel to project, etc., should be charged directly to the 
activity concerned, 1. e., Control, Topography, or Estimate, or prorated over them, 
as the case may be. 

Note 2. Area, cost per acre, and total area to date for intensive and extensive 
timber surveys, by fiscal years, will be supplied on Form 446 as heretofore, 

A systematic diagram map record of areas covered by inten- 
sive timber surveys will be maintained for the Forester's and 
district forester's files. These maps will be kept current annu- 
ally, by Forests, and should contain the following information : 

(1) All areas of one section or more in extent which have 
been covered by intensive timber surveys, whether conducted 
by special crews or by National Forest personnel. On each 
area should be entered the date when the work was done. 

(2) All areas included in Forester's or district forester's 
sales, past and present. A number should be placed within each 
sale area and the designation of the sale entered under the 
same number on the margin of the map. In the case of con- 



EQUIPMENT. 37 

tracts canceled before completion a line should be drawn through 
the number designating the sale area in question. A subse- 
quent sale covering the same area will then be designated by 
another number, or changes in the boundary of the new sale 
can be readily indicated without confusion. 

(3) Areas cut over under sale contracts indicated by hatching 
the proper portion. 

In order to secure uniformity the data shown on maps sub- 
mitted to the Forester will be indicated in the following 
ways: 

(1) Outline and hatch areas covered by timber surveys in 
green ink. 

(2) Outline sale areas and number them in red ink; use 
black ink in striking out numbers to indicate cancellation of 
sales before completion. 

(3) Indicate cut-over areas by hatching in red ink. 

The diagram maps on file in the Forester's office will be 
returned each winter to the districts to be brought up to date. 

EQUIPMENT. 

Unless other arrangements are made by the district forester, 
all equipment should be secured through the supervisor, who 
will be responsible for having a sufficient quantity of suitable 
and necessary instruments and other equipment, forms, sup- 
plies, etc., on hand well before the project starts. The super- 
visor should have sufficient advance notice from the district 
forester after the preparation of the plan to permit his com- 
plying with this requirement. Foresight in this respect is 
necessary to avoid needless and costly delays after the crew is 
organized. 

Each district should include in its district instructions a list 
of standard equipment for parties of a given size. For equip- 
ment required in conducting surveys see Instructions for Mak- 
ing Topographic Surveys and Maps. Criticisms of equipment 
should be forwarded to the Forester through the district forester, 
accompanied by suggestions for improvement. 



STANDARD CLASSIFICATION OF FOREST 
TYPES. 

(Revised February 1, 1917.) 

The following standard classification of forest types will 
hereafter be the basis for all descriptive and mapping work 
in the National Forests, including grazing, as far as possible, 
without necessitating a departure from the approved type 
classification for grazing reconnaissance. It will be used in 
boundary, timber survey, timber sale, and general administra- 
tive work, and in all agricultural classification work except 
soil classification proper. Where further subdivision appears 
to be necessary in studies of yield or other investigations, 
approval of the new types proposed will be secured in advance. 

The classification hereafter outlined is based upon the pres- 
ent composition of the stand, regardless of whether this com- 
position is the ultimate cover of the site or merely a temporary 
cover resulting from some interference with natural conditions. 
Where a succession of types is known to occur, either the ulti- 
mate type or one of the stages in the succession which, as far 
as can now be foreseen, will be perpetuated in forest manage- 
ment, may, if desired, be mapped or used for purposes of 
management in addition to the present cover. 

No attempt has been made to provide for all possible com- 
binations of species, but a rather broad practical division has 
been used. Only such types as occupy sufficient area to be 
of importance in forest management have been included. 

The name is taken wherever possible from the most distinc- 
tive commercial species or key tree occurring in the type, 
whether or not most of the stand is of this species. 

The presence or absence of key trees or combinations of 
trees will often be found helpful in determining how to classify 
38 



STANDARD CLASSIFICATION. 39 

any given stand. Keeping in mind the tree or trees which will 
be favored in cutting and the conditions which these trees 
require for successful growth will also assist the field men in 
distinguishing types. 

The percentages given in the type descriptions are percent- 
ages of the number of the trees 8 inches and over in diameter, 
or of the trees which form the main stand and those which it is 
reasonable to suppose will eventually come up into the main 
stand. Thus, for example, in the Enge^mann spruce type the 
young growth is often predominantly fir, alpine, or cork bark, 
most of which dies off before it becomes large enough to form 
part of the main stand. When, in a very mixed stand, the 
proportion of no one species comes up to the proportion named 
in the definition, the area will be thrown into the type which it 
most resembles, or the prevailing type in the immediate locality. 

Burns, except for repeatedly burned areas which contain 
neither reproduction, grass, nor brush in appreciable quantities 
and are classified as barren, should not be classified as a dis- 
tinct type. The presence of reproduction or burned timber, or 
both, is sufficient to make possible their mapping in accordance 
with the following classification. There is no objection, how- 
ever, to indicating the area of the burn if desirable or neces- 
sary by a combination of the burn and type symbols. 

The terms cover, temporary, permanent, and physical types 
are used with the following meaning: 

A cover type is a forest type now occupying the ground. 
The term conveys no implication as to whether the type is tem- 
porary, or permanent, or one which we shall strive to maintain 
under forest management. 

A temporary type is a forest type which has come in as a re- 
sult of some interference with natural conditions, such as fire 
or lumbering, and which will eventually, if nature is left un- 
disturbed, be replaced by a different type. 

A permanent type, or natural type, also called ultimate or 
climax type, is a forest type which eventually will take pos- 
session of and perpetuate itself on any given area if natural 
conditions are undisturbed. 



40 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

A physical type is understood to be an area considered with 
reference to its forest-producing power, as determined by the 
physical factors of the site. It refers to the land and not to 
the stand, although the stand, particularly in the case of per- 
manent types, may be an excellent indication of the physical 
type, and is synonymous with " site " or " locality." 

No standardization of physical types is being attempted at 
this time, since it is felt that further investigations are neces- 
sary to place such a classification on a sound basis. There is 
no objection, however, *to the use by any district of such types, 
in addition to the forest type classification called for here, pro- 
vided it is believed that such a classification is necessary, of 
practical value, and the data can be obtained without overload- 
ing timber survey crews. 

DESCRIPTIONS OF TYPES. 

TREELESS LAND. 

There is no clear line of demarcation between trees and 
shrubs ; and in this classification, which is purely for practical 
purposes, no attempt is made to draw a fine distinction between 
them. Accordingly, under " Treeless land " are included three 
types — " Brush," " Sagebrush," and " Chaparral " — which often 
are composed partly or entirely of individuals having tree form, 
but so small and stunted that the types in which they occur 
are classified ordinarily as treeless. 

Barren. ^ All districts. 

An area too rocky, too exposed, too arid, or at too high an 
elevation to support trees or grass or more than a very scatter- 
ing growth of herbs and shrubs ; or an area so repeatedly 
burned that it contains neither reproduction, grass, nor brush 
in appreciable quantities. 

Grass. All districts. 

An area, such as a park, mountain meadow, or treeless ridge, 
whose principal vegetation is grass and other herbs. 



DESCRIPTIONS OF TYPES. 41 

Cultivated. All districts. 

An area now under cultivation or lying fallow. 
Chaparral. District 5. 

An area too arid to support a nominal tree growth, but bear- 
ing a permanent cover of shrubs or stunted trees, occurring in 
southern California. 

Sagebrush. Districts 1, 2, 3, 4, 5, and 6. 

An area whose principal vegetation is sagebrush. 
Brush. All districts. 

All other areas the present cover of which is a stand of shrubs 
or stunted trees. 

WOODLAND. 

An area, usually at the lower altitudinal limits of tree 
growth, whose crop when mature is a stand of trees, ordinarily 
open, usually short, branchy, and crooked, most of which are 
fit only for cordwood, fencing, etc. 

Pifion-Juniper. Districts 2, 3, 4^ and 5. 

A stand composed of approximately 80 per cent or more of 
piSion and juniper in varying proportions. 

District 2. — Pinon (Pinus edulis), Rocky Mountain juniper 
(Juniperus scopulorum), and one-seed juniper {J. monosperma) 
are the chief species, often with some Gambel oak iQuercus 
gamhelii) and western yellow pine. 

District 3. — Piiion, Mexican pinon (P. cemhroides), single- 
leaf pinon (P. monophylla) , alligator juniper (Juniperus 
pachyphloea) , one-seed juniper, Rocky Mountain juniper, and 
Utah juniper (J. utahensis) are the chief species, often with 
some Gambel oak and western yellow pine. 

District 4- — Single-leaf pinon, Utah juniper, one-seed juniper, 
and Rocky Mountain juniper are the chief species, often with 
some Gambel oak and western yellow pine. 

District 5. — Single-leaf pinon and Utah juniper are the chief 
species, often with some western juniper (J. occidentaUs) and 
Jeffrey pine. 



42 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

Juniper. Districts 1, 5, and 6. 

A stand composed of approximately SO per cent or more of 
any species of juniper, with very little or no pinon. 

District 1. — Rocky Mountain juniper is the chief species, 
usually with some limber pine, western yellow pine, or Douglas 
fir. 

District 5. — Western juniper is the chief species, often with 
some Jeffrey pine and western yellow pine. 

District 6. — Western juniper is the chief species, often with 
mountain mahogany, and sometimes with a little western 
yellow pine. 

Oak. Districts 3, 4, 5, and 6. 

A stand composed of approximately 60 per cent or more of 
any species of western oaks. 

District 3. — Emory oak {Q. emoryi), Arizona white oak (Q. 
arizonica), blue oak {Q. oUongifolia) , and whiteleaf oak (Q. 
hypoleuca) are the chief species, often with some alligator 
juniper, Mexican pinon, and other species. 

District If. — Gambel oak is the chief species, and is usually 
pretty scrubby. 

District 5. — California black oak (Q. calif ornica), California 
rock oak {Q. douglasii), canyon live oak {Q. chrysolepis) , Cali- 
fornia live oak (Q. agrifolia), highland oak (Q. wislizeni), 
California white oak (Q. lohata). and Garry oak (Q. garryana) 
are the chief species, often with some digger pine, madrone, 
and occasionally some knobcone pine, Coulter pine, Jeffrey 
pine, western yellow pine, and other species. 

District 6. — Garry oak is the chief species, sometimes pure; 
more often it is mixed with California black oak, tanbark oak, 
madrone, myrtle, etc. 

Digger Pine. District 5. 

A stand containing approximately 40 per cent or more of 
digger pine, often mixed with various oaks, Coulter pine, west- 
ern yellow pine, and other species. Occurs on any sites below 
the western yellow pine type. 



DESCRIPTIONS OF TYPES. 43 

TIMBERLAND. 

An area whose crop when mature is a more or less dense 
stand of trees which may furnish sawlogs, ties, telegraph 
poles, etc. 

Yellow Pine. Districts 1, 2, 3, 4, 5, and 6. 

A stand containing approximately 50 per cent or more of 
western yellow pine, except where sugar pine is the key tree. 
Usually on dry well-drained sites at the lower altitudinal limit 
of timberland or exposed south and southwest slopes at higher 
altitudes. 

District 1. — The principal species in mixture are Douglas fir, 
western larch, and lodgepole pine. 

District 2. — The principal species in mixture are Douglas fir, 
white fir, blue spruce, and lodgepole pine. 

District 3. — The principal species in mixture are Douglas fir 
and white fir, and rarely blue spruce. 

District Ji. — The principal species in mixture are Douglas fir, 
white fir, western larch, and lodgepole pine. An exception may 
be made in the case of distinct yellow-pine land containing less 
than 50 per cent of yellow pine, which may be mapped as yel- 
low pine. 

District 5. — The principal species in mixture are Jeffrey pine, 
incense cedar, sugar pine, Douglas fir, and white fir. 

District 6. — The principal species in mixture are western 
larch, Douglas fir, white fir, grand fir, lodgepole pine, and sugar 
pine. 

Jefifrey Pine. District 5. 

A stand containing approximately 40 per cent or more of 
Jeffrey pine. Western yellow pine and white fir are often 
abundant, and there is usually some Coulter pine, incense cedar, 
or other species. At either low or high elevations, but almost 
invariably on the drier, less favorable and more exposed sites. 

Sugar Pine-Yellow Pine. Districts 5 and 6. 

A mixed stand in which sugar pine is the key tree forming 
approximately 15 per cent or more of the stand, and in which 



44 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

yellow pine and incense cedar are its usual associates. Other 
species which occur in varying proportions are white fir, Doug- 
las fir, bigtree, and Jeffrey pine. Such areas will be included 
in this type even though otherwise conforming to the definition 
of the yellow-pine type. Usually at moderate elevations and on 
favorable sites between the western yellow pine and fir types. 

Sugar Pine-Fir. District 5. 

Distinguished from the sugar pine-yellow pine type by the 
absence of yellow pine. Species in mixture are Douglas fir, 
white fir, and a very little incense cedar; at higher elevations, 
red fir. The type occurs chiefly in California north of the point 
where the Sierras lose their distinctive crest. 

Western White Pine. District 1. 

A stand in which western white pine is the key tree, forming 
approximately 15 per cent or more of the stand. In the north- 
ern part of the range of this type, at medium elevations, hem- 
lock is the predominant tree, frequently outnumbering the white 
pine even in young stands; at higher elevations in the same 
region Engelmann spruce and alpine fir are the chief associates. 
In the middle of its range white pine occurs nearly pure or with 
Douglas fir as its chief associate, and with hemlock, white fir, 
larch, and sometimes lodgepole pine in mixture. In the south- 
ern part of the range of this type white pine is less important 
numerically than farther north. Here in young stands white 
pine occasionally forms as much as 50 per cent of the stand or 
more, but usually the predominant trees of the type are white 
fir and cedar, with Douglas fir and larch in mixture, a little 
yellow pine on the drier knolls, and sometimes in young stands 
lodgepole pine. 

Lodgepole Pine. Districts 1, 2, 4, 5, and 6. 

A stand containing approximately 50 per cent or more of 
lodgepole pine, usually nearly pure, but sometimes in mixture 
with other species. 



DESCRIPTIONS OF TYPES. 45 

District 1. — The principal species in mixture are Douglas fir, 
Engelmann spruce, alpine fir, and western larch. 

District 2. — The principal species in mixture are Douglas fir, 
Engelmann spruce, alpine fir, blue spruce, bristlecone pine 
(P. aristata), and limber pine (P. flexilis). 

District Jf. — The principal species in mixture are Douglas fir, 
alpine fir, and Engelmann spruce. 

District 5. — The principal species in mixture are white fir, 
red fir, and occasionally white pine. Stands with less than 50 
per cent of lodgepole pine should be classed as the subalpine or 
fir type. 

District 6. — The principal species in mixture are Douglas fir, 
alpine fir, yellow pine, grand or white fir, mountain hemlock, 
western larch, and silver fir. The type occurs along the ocean 
beach, on the pumice fiats of the central Oregon Plateau, and at 
the higher elevations, as in the other districts. 

Bristlecone Pine. District 2. 

A stand containing approximately 60 per cent or more of 
bristlecone pine, often in mixture with limber pine, lodgepole 
pine, Engelmann spruce, blue spruce, Douglas fir, and white fir. 
Usually on dry, rocky, wind-swept sites at the higher elevations. 

Douglas Fir. Districts 1, 2, 3, 4, 5, and 6. 

A stand containing approximately 60 per cent or more of 
Douglas fir. 

District 1. — The principal species in mixture are yellow pine, 
lodgepole pine, and western larch. Usually at the lower or 
medium altitudes, either at the lower limit of timberland or just 
above the yellow-pine type. Occurs also on north slopes above 
the white-pine type. 

District 2. — The principal species in mixture are yellow pine, 
lodgepole pine, limber pine, white fir, and blue spruce. Usually 
at medium elevations and on poor or fairly favorable sites and 
moderately warm exposures. 



46 INSTRUCTIONS FOR MAKING TIMBER SURVEYS. 

District 3. — The principal species in mixture are yellow pine 
and white fir. Usually at medium altitudes between the yellow 
pine and Engelmann spruce types. 

District 4- — The principal species in mixture are western 
yellow pine, lodgepole pine, and western larch. Usually at 
medium elevations between the yellow pine and lodgepole pine 
or Engelmann spruce types. 

District 5. — The principal species in mixture are yellow pine, 
sugar pine, incense cedar, and white fir. Usually at medium 
elevations on fairly favorable sites. Nearly always on north 
and east slopes or moist bottoms. 

District 6. — The characteristic forest west of the Cascades, 
occurring as pure stands of Douglas fir, or Douglas fir mixed 
with hemlock, cedar, and other species, such as Sitka spruce, 
Lawson cypress, grand fir, western white pine, silver fir, and 
rarely lodgepole pine. 

Douglas Fir-Spruce. District 4. 

A stand containing approximately 60 per cent or more of 
Douglas fir and Engelmann spruce in varying mixtures. Other 
species in mixture are western yellow pine, lodgepole pine, 
and western larch. Usually at medium elevations between the 
yellow pine and the lodgepole pine or Engelmann spruce types. 
Cedar-White Fir. District 1. 

A stand composed of cedar and white or grand fir, the former 
nearly pure in patches; the latter predominant throughout, 
with a considerable amount of Douglas fir, some yellow pine 
in grouios on the knolls and as scattered individuals throughout, 
and rare western white pine individuals. The type occurs on 
the Selway National Forest and the southern portion of the 
Clearwater National Forest south of the commercial range of 
white pine. 

Cedar-Hemlock-White Fir. District 1. 

A stand composed of cedar, hemlock, and white or grand 
fir in varying proportions, with a little white pine, also Engel- 
mann spruce, alpine fir, and rarely Douglas fir. Areas which 



DESCRIPTIONS OF TYPES. 47 

under management could be made to produce white pine in 
commercial Quantities. 

Larch-Douglas Fir. Districts 1 and 4. 

A stand containing approximately 60 per cent or more of 
western larch and Douglas fir with white or grand fir in mixture. 
Larch is the l^ey tree. The proportion of larch varies greatly, 
from very little to practically pure. 

District 1. — The principal species in mixture is yellow pine, 
occasionally with lodgepeople pine, western white pine, lowland 
fir, western red cedar, or western hemlock. Usually at medium 
elevations, about the same as Douglas fir, but on more favorable 
sites. On less favorable sites than white pine. 

District It. — The principal species in mixture are yellow pine 
and lodgepole pine, white or grand fir, and Engelmann spruce. 
Usually at about the same elevation as the Douglas-fir type, but 
on slightly more favorable sites. 

White Fir-Larch-Douglas Fir. District 6. 

A stand containing approximately 60 per cent or more of 
western larch, white fir, grand fir, and Douglas fir, with some 
western yellow pine and lodgepole pine, but with yellow pine 
in the minority. Within its range western larch is the key tree. 
The proportion of each species varies greatly, from very little 
to practically pure. A prevalent type on the north and cool 
slopes within the yellow-pine zone ; of secondary commercial 
importance and very variable mixture. 

Western Hemlock. District 6. 

A stand containing approximately 50 per cent or more of west- 
ern hemlock, usually, in mixture with one or more of the follow- 
ing: Douglas fir, western red cedar, grand fir, and silver fir. 
Found west of the Cascades on situations similar to those on 
which the Douglas fir type occurs ; also on higher situations. 

Cedar. District 6. 

A mixed forest in which cedar is the important commercial 
species, usually comprising 40 per cent or more of the stand, the 



48 INSTKUCTIONS FOR MAKING TIMBER SURVEYS. 

associates being hemlock, grand fir, silver fir, Douglas fir, and 
sometimes a little Sitka spruce. It is found principally in valley 
bottoms on either side of the Cascades, but chiefly on the west 
side, contiguous to the Douglas fir or the western hemlock type. 

Engelmann Spruce. Districts 1, 2, 3, and 4. 

A stand containing approximately 50 per cent or more of 
Engelmann spruce. Sometimes follows a temporary type of 
aspen. 

Districts 1, 2, and 4. — Engelmann spruce may be pure, but is 
more often in mixture with alpine fir, lodgepole pine, limber pine, 
Douglas fir, and occasionally, in District 2, bristlecone pine. 
Usually at the higher elevations and on the moister sites. 

District 3. — Engelmann spruce may be pure, but is more often 
in mixture with alpine fir, Douglas fir, bristlecone pine, or cork- 
bark fir. At the higher elevations, usually at the upper limit of 
timberland. 

Sitka Spruce. District 6. 

A stand composed predominantly (usually at least 60 per cent) 
of Sitka spruce. It is found chiefly on valley bottoms and benches 
on the west side of the Olympic and Coast mountains. 

Fir. Districts 3, 4, 5, and 6. 

A stand containing approximately 50 per cent or more of one 
or more species of the true firs. White fir, alpine fir, red fir, 
Shasta fir, noble fir, and silver fir, either in combination or 
singly, usually predominate, with grand fir in smaller quan- 
tities. 

District 3. — A stand containing 50 per cent or more of white 
fir. The chief tree in mixture is Douglas fir, associated with 
Engelmann spruce, alpine fir, and cork-bark fir at the higher 
elevations, and with yellow pine at the lower elevations. 

District 4- — A stand containing approximately 60 per cent or 
more of white fir, alpine fir, or grand fir, either in combination 
or singly, with a varying mixture of Douglas fir, Engelmann 
spruce, and lodgepole pine. It is found at varying elevations, 



DESCRIPTIONS OF TYPES. 49 

depending on the exposure, within the Douglas tir and Engel- 
mann spruce zones. 

District 5. — ^A stand containing approximately 50 per cent or 
more of white fir, red fir, or Shasta fir; often in mixture with 
western white pine, sugar pine, mountain hemlock, and lodge- 
pole pine, the last scattered or in pure patches ; occasionally 
mixed with Jeffrey pine, incense cedar, and Douglas fir. At 
the higher elevations and on cool, moist sites. 

District 6. — ^A stand characterized by noble, silver, Shasta, 
or red fir, either in mixture or singly. Other species in mixture 
are Douglas fir, western hemlock, mountain hemlock, western 
white pine, lodgepole pine, white fir, grand fir, western larch, 
and yellow cedar (O. nootkatensis) . It is the characteristic 
type of certain situations on the upper slopes of the Cascades, 
usually above Douglas fir and hemlock types on the west and 
above the yellow pine and white fir-larch-Douglas fir types 
on the east of the Cascades. The key trees are silver fir and 
noble fir in the northern part and Shasta fir and red fir in the 
southern part of the district. 

Red Fir. District 5. 

A stand containing at least 75 per cent of red fir {Ahies 
magniflca) or Shasta fir (A. shastensis) , usually at the higher 
elevations below the subalpine type. 

Mountain Hemlock. •Districts 1 and 6. 

A stand containing approximately 50 per cent or more of 
mountain hemlock (T. mertensiana) . Other species common in 
the mixture are alpine fir, silver fir, Shasta fir, alpine larch 
{L. lyalli), white-bark pine, lodgepole pine, western white 
pine, and Engelmann spruce. At the higher elevations usually 
near the upper limit of tree growth. Areas of mountain hem- 
lock not capable of producing merchantable stands should be 
included in the subalpine type. 

District 1. — The principal species in mixture are alpine fir, 
Engelmann spruce, and western white pine. 

86656—17—4 



50 INSTRUCTIONS FOE MAKING TIMBER SURVEYS. 

District 6. — The principal species in mixture are alpine fir, 
silver fir, lodgepole pine, alpine larch, and western white pine. 

Subalpine. Districts 1, 2, 3, 4, 5, and 6. 

A stand containing a varying mixture of subalpine species, 
no one of which is abundant enough to throw the stand into 
any of the types already described, or rarely pure stands. At 
the upper limit of tree growth, usually unmerchantable because.' 
of poor form and small size, and of value for protective pur 
poses only. 

District 1. — Tlie principal species are alpine fir, Engelniun:i 
spruce, lodgepole pine, white-bark pine, limber pine, mountaii' 
hemlock, and alpine larch. 

District 2. — The principal species are alpine fir, Engelmanii 
spruce, lodgepole pine, limber pine, and bristle-cone pine. 

District 3. — The principal species are Engelmann spru'c. 
bristle-cone pine, limber pine, and dwarf juniper. 

District .^.— The principal species are alpine fir, Engelmann 
spruce, lodgepole pine, white-bark pine, and limber pine. 

District 5. — The principal species are red fir, Shasta fii'. 
white fir. lodgepole pine, white-bark pine, western white pine, 
foxtail pine, and mountain hemlock. 

District 6. — Usually characterized by alpine fir, but not neces- 
sarily containing a majority of this species : also has Shast:' 
fir, noble fir, lod^pole pine, white-bark pine, western white 
pine, mountain hemlock, and alpine larch. It is a type whicli 
does not produce saw logs. 

Redwood. Districts 5 and 6 

A stand containing approximately 80 per cent or more of red- 
wood, usually with some Douglas fir, madrone, tanbark oak, 
and other smaller hardwoods. In situations at low elevations 
along the coast in California and southern Oregon. 

Aspen. Districts 2, 3, and 4. 

A stand containing approximately 60 per cent or more of 
aspen, often nearly pure, but sometimes with various conifer.^ 
in mixture. At medium to high elevations, but usually on fairly 



DESCKIPTIONS OF TYPES. 51 

uioist sites. Where desired and clearly practicable aspen 
stands may be mapped as young age clashes of the type com- 
prising the coniferous understory. 

District 2. — The type may or may not have an understory 
of Engelmann spruce, alpine fir, Douglas iir, or yellow pine. 

District 3. — The type has generally an understory of Engel- 
mann spruce, cork-bark fir, and alpine fir, indicating an Engel- 
mann spruce permanent type, or Douglas fir and white fir, 
indicating a Douglas fir or a fir permanent type. 

District 4. — The type may or may not have an understory of 
Douglas fir, white fir, and p]ngelmann spruce. 
Bottomland Hardwoods. District 6. 

A stand consisting largely (usually 80 per cent or more) of 
any one or a mixture of the following species : Alder, black 
cottonwoods, broadleaf maple, Oregon ash. It is usually found 
on bottom lands or moist slopes at low elevations in western 
Oregon and Washington, where it is often a temporary typo 
which is ultimately replaced by a coniferous forest. 

Jack Pine. District 2 (Lake States). 

A stand containing approximately 50 per cent or more of jack 
pine, occasionally mixed with Norway pine and often with a 
number of species of scrubby oaks. On the driest, sandiest soils. 

Norway Pine. District 2 (Lake States). 

A stand containing approximately 50 per cent or more of Nor- 
way pine, sometimes mixed with jack pine, white pine, hemlock, 
and several species of oak. On dry, sandy soils, slightly better 
than those characteristic of the jack-pine type. 

White Pine. District 2 (Lake States). 

A stand containing approximately 50 per cent or more of white 
pine, often mixed with Norway pine, hemlock, and a number of 
hardwood species. Usually on moderately moist, well-drained 
soil of better quality than that characteristic of the red-pine 
type. 



52 INSTEUCTIONS FOR MAKING TIMBER SURVEYS. 

Scrub Oak. District 2 (Lake States). 

A stand containing a mixture of scrubby red, black, and scarlet 
oaks, with an occasional white oak, and some jack pine. Usually 
on sandy soil intermediate between that characteristic of the 
jack-pine and Norway-pine types. 

Birch-Beech-Maple. District 2 (Lake States). 

A stand composed chiefly of yellow birch, beech, sugar maple, 
and occasionally white elm, basswood, white oak, and conifers. 
On good or moderately good soils. 

White Spruce. District 2 (Lake States and Black Hills). 

A stand containing approximately 50 per cent or more of white 
spruce. In the Black Hills it is usually nearly pure, while in 
the Lake States it is usually mixed with balsam fir, arborvitse, 
tamarack, and occasionally black spruce, and white pine. 
Usually on wet soils, but with good drainage. 

Arborvitae. District 2 (Lake States). 

A stand containing approximately 80 per cent or more of 
arbor vitre (T. occldentaUs) , sometimes mixed with tamarnck or 
black spruce. Usually in shallow swamps on good soil without 
peat. 

Tamarack-Spruce. District 2 (Lake States). 

A stand containing approximately SO per cent or more of 
tamarack or black spruce, either in combination or singly, occa- 
sionally with some arborvit?e or balsam fir. Usually in distinct 
swamps, often with some peat. 

Longleaf Pine. District 7. 

A stand containing approximately 80 per cent or more of long- 
leaf pine, sometimes mixed with Cuban pine and with an under- 
growth of turkey, blackjack, and live oaks. On the drier, 
sandier soils. 



DESCEIPTIONS OF TYPES. 53 

Titi. District 7. 

Dense, junglelike swamps along the streams ; composed of a 
great variety of species, all of which, except titi (Cliftonia 
monophylla), occur only scatteringly. 

Shortleaf Pine. District 7. 

A stand containing approximately 50 per cent or more of short- 
leaf pine, sometimes pure, but more often in mixture with vari- 
ous oaks and other hardwoods. Usually on the drier slopes. 

White Oak. District 7 (Arkansas). 

A stand composed chiefly of a varying mixture of white oak, 
red oak, post oak, black oak, hickory, black locust, black walnut, 
black gum, black cherry, beech, cottonwood, ash, willow, etc., 
and containing less than approximately 50 per cent of shortleaf 
pine. In nearly all situations, bottom, slope, and ridge. White 
oak is the key tree and predominates in most places. 



